There is growing concern for the release of greenhouse gases into the atmosphere including in particular carbon dioxide because of its ability to trap heat. Technology exist for the recovery of carbon dioxide from flue gases; i.e. gases resulting from the combustion of coal, oil and/or natural gas, but to date the application of this know how has been limited. Focusing on the recovery of carbon dioxide while ignoring the questions of storage and disposal two approaches for carbon capture have been proposed. Carbon dioxide can either be recovered by absorption on a solid absorbent or dissolved in an aqueous solution. In the first instance, such solid materials can include carbon, small zeolites and metal organics. Absorption, however, presents challenges in that care must be taken to avoid attrition of the solid absorbent
The proposal for carbon capture in a solvent commonly involves an aqueous solution of amine. The amine of choice is monoethanolamine. While this solvent is sufficient in scrubbing flue gases, its regeneration is problematic because of the need for relatively high temperatures.